Homogeneous cosmetic stick products

ABSTRACT

This invention provides an antiperspirant-deodorant cosmetic stick product consisting of a solid organic matrix which contains a homogenous dispersion of particulate antiperspirant and deodorant ingredients. A deodorant cosmetic stick product is also provided which does not contain an antiperspirant ingredient. 
     The solid organic matrix and dispersed particle phases have densities which are sufficiently matched to prevent setting of the dispersed particles during manufacture, and to provide a cosmetic stick product with dimensional stability.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This application is a division of application Ser. No. 07/986,810, filedDec. 8, 1992 pending.

The subject matter of the present invention is related to that describedin patent application Ser. No. 07/986,917, filed Dec. 8, 1992, now U.S.Pat. No. 5,378,456; and patent application Ser. No. 07/986,916, filedDec. 8, 1992, now U.S. Pat. No. 5,354,553.

BACKGROUND OF THE INVENTION

Antiperspirants combat axillary odors by inhibiting perspiration throughthe action of astringent salts such as aluminum and zinc salts, but maybe irritating to a large number of users. Deodorants function byneutralizing the objectionable odors resulting from the degradation ofseveral components of perspiration by chemical and microbial action intomalodorous fatty acids.

Numerous solid antiperspirant and/or deodorant compositions have beendescribed in the chemical and cosmetic literature. These compositionsgenerally are emulsion sticks or suspensoid sticks. Emulsion stickscontain a solution of the antiperspirant ingredient incorporated intothe stick via an emulsion. Although emulsion sticks are desirable incertain respects, they tend to be unstable, exhibit tackiness, and leavea visible residue on the skin after use. Suspensoid sticks contain thepowdered antiperspirant ingredient suspended in the stick without theuse of water or an emulsion. While suspensoids have stability, they tendto leave a white chalky residue on the skin after application.

Manufacturers have found that anhydrous antiperspirant stick systems aremore marketable and have good consumer acceptance primarily due to theease of application to the skin, good cosmetic esthetics and anacceptable degree of effectiveness. Previous to the development ofanhydrous stick systems, numerous water based systems were developed inwhich the active astringent salts were solubilized in a thickened orgelled composition. This is exemplified in U.S. Pat. Nos. 2,732,327;2,857,315; 3,255,082; and 3,928,557. The water based systems aredifficult to apply to the skin, and their consistency and effectivenessare variable.

Many anhydrous stick compositions have been described in the literaturewhich attempt to improve the delivery and the effectiveness of theirantiperspirant and deodorant characteristics. Antiperspirant sticksystems consisting of low molecular weight monohydric alcohols inconjunction with polyhydric alcohols are described in U.S. Pat. No.4,137,306. These sticks have the advantage of quicker drying rates, butthe residue of the polyhydric alcohols in combination with theastringent salts produces a high degree of tack, and their effectivenessis limited to the type and amount of astringent salts that could beincorporated in the stick matrix.

Anhydrous stick compositions that suspend the aluminum salt in ahydrophobic matrix are described in U.S. Pat. No. 4,049,792. Thesecompositions employ waxy materials and long chain fatty esters to form astick that delivers the active astringent salts to the skin.

Cosmetic stick compositions made in accordance with these embodimentsare greasy, and the active astringent salt is enveloped in a manner thatprevents maximum performance. To alleviate this inherent negativecharacteristic, volatile silicone fluids replacement of the lessvolatile long chain fatty esters is described in U.S. Pat. No.4,126,679. This disclosure teaches the advantage of utilizing a volatilenon-staining liquid such as cyclic dimethylpolysiloxanes (referred to asvolatile silicones), in combination with various types of waxes, as acarrier for the active astringent salts in an antiperspirant stickcomposition. Similar antiperspirant stick compositions containingvolatile silicones are described in U.S. Pat. Nos. 4,511,554; 4,980,156;and 4,985,238.

With respect to deodorant activity, sodium bicarbonate has long beenrecognized for deodorant properties, and has commonly been used as ahousehold deodorant. Plain powdered sodium bicarbonate, or sodiumbicarbonate diluted with talc or other filler, has been used as anunderarm deodorant as disclosed in U.S. Pat. No. 4,382,079. Otherpublications which describe cosmetic stick compositions containing abicarbonate deodorant include U.S. Pat. Nos. 4,822,602 and 4,832,945.

However, the development of a practical and effective antiperspirantcomposition in cosmetic stick form which is also capable ofdeodorization, and which is capable of consumer acceptability, presentsmany factors which are unique. Because sodium and potassium bicarbonatehave only limited solubility in water, alcohol and other solvents, thepreparation of a composition suitable for dispensing in cosmetic stickform has involved many processing obstacles. In addition to the problemof limited solubility, sodium bicarbonate is incompatible with theactive astringent salts and with other ingredients of conventional stickcompositions. Also, the dimensional stability of the cosmetic stickcontaining sodium bicarbonate, and the esthetic appearance and the"feel" on the skin, are just a few of the additional difficultiesencountered in the preparation of a low residue antiperspirant-deodorantcosmetic stick product.

Another significant problem associated with the incorporation of abicarbonate deodorant ingredient in a cosmetic stick formulation is thetendency for the high density bicarbonate salt particles to settle inthe fluid medium during processing. Also, under the elevated temperatureconditions required for the admixing and blending of ingredients,bicarbonate degradation and evolution of carbon dioxide occur.

There is continuing interest in the development of improved cosmeticstick products which exhibit antiperspirant and/or deodorant activity,and in processes for their preparation.

Accordingly, it is an object of this invention to provide a process forthe manufacture of a cosmetic stick product which exhibits deodorantproperties, and is characterized by excellent esthetics and cosmeticproperties.

It is another object of this invention to provide a homogeneousantiperspirant-deodorant cosmetic stick product which contains adispersed phase of particulate antiperspirant and deodorant ingredientsin a solid organic matrix phase, and which phases are density matched toprevent settling of the dispersed particles.

Other objects and advantages of the present invention shall becomeapparent from the accompanying description and examples.

DESCRIPTION OF THE INVENTION

One or more objects of the present invention are accomplished by theprovision of an antiperspirant-deodorant cosmetic stick productconsisting of a solid organic matrix comprising the following parts byweight of ingredients:

    ______________________________________                                        volatile silicone oil   10-50                                                 liquid emollient         1-30                                                 low melting point wax   12-24                                                 ______________________________________                                    

and the solid organic matrix has homogeneously dispersed therein betweenabout 18-35 parts by weight of particulate antiperspirant and betweenabout 0.05-30 parts by weight of particulate water-soluble inorganicsalt deodorant ingredients; wherein the dispersed particles have adensity which is less than about one gram per cubic centimeter higherthan the density of the solid organic matrix.

The particulate antiperspirant and deodorant ingredients typically havean average particle size between about 5-200 microns.

The density of the solid organic matrix is between about 0.8-1.6 gramsper cubic centimeter, and the density of the antiperspirant anddeodorant particles is between about 0.9-2 grams per cubic centimeter.

In another embodiment this invention provides a process for preparing anantiperspirant-deodorant cosmetic stick product which comprises (1)heating and forming a liquid organic matrix of ingredients comprisingbetween about 10-50 parts by weight of a volatile silicone oil; betweenabout 1-30 parts by weight of a liquid emollient, and between about12-24 parts by weight of a low melting point wax; (2) adding anddispersing in the heated liquid organic matrix between about 18-35 partsby weight of particulate antiperspirant and between about 0.05-30 partsby weight of particulate water-soluble inorganic salt deodorant to forma homogeneous fluid suspension medium; and (3) dispensing the heatedfluid suspension medium into cosmetic stick containers, and cooling thecontainer contents to form solid sticks at room temperature; wherein thedispersed particles have a density which is less than about one gram percubic centimeter higher than the density of the organic matrix in thecosmetic stick product.

In a preferred embodiment between about 0.5-5 parts by weight of asurfactant ingredient is included in the step (2) formation of theliquid organic matrix.

An invention antiperspirant-deodorant cosmetic stick product typicallycontains the following weight proportions of main ingredients:

    ______________________________________                                        Ingredient              Weight                                                ______________________________________                                        volatile silicone oil   25-50                                                 liquid emollient         2-20                                                 wax (MP 95°-180° F.)                                                                    15-20                                                 antiperspirant          20-30                                                 bicarbonate deodorant   0.1-25                                                surfactant              1-3                                                   ______________________________________                                    

In another embodiment this invention provides a cosmetic stick productas described above which contains a deodorant ingredient but does notcontain an antiperspirant ingredient.

An invention deodorant cosmetic stick product can contain the followingweight proportions of main ingredients:

    ______________________________________                                        Ingredient              Weight                                                ______________________________________                                        volatile silicone oil   10-55                                                 liquid emollient         1-35                                                 wax (MP 95°-180°F.)                                                                     12-30                                                 bicarbonate deodorant    1-40                                                 surfactant              0.5-5                                                 ______________________________________                                    

The volatile silicone oil ingredient in an antiperspirant-deodorantcosmetic stick product of the present invention preferably is a cyclicor linear polydimethylsiloxane containing between about 3-9 siliconatoms. A suitable cyclic volatile polydimethylsiloxane compound isillustrated by the formula: ##STR1## where n is an integer with a valueof about 3-7.

A suitable linear polydimethylsiloxane is illustrated by the formula:

    (CH.sub.3).sub.3 Si--O[Si(CH.sub.3).sub.2 --O].sub.n --Si(CH.sub.3).sub.3

where n is an integer with a value of about 1-7.

Linear volatile silicone compounds generally have viscosities of lessthan about 5 centistokes at 25° C., while the cyclic type compounds haveviscosities of less than about 10 centistokes.

Typical of the volatile silicone compounds that can be employed forpurposes of the present invention is cyclomethicone, which is a cyclicdimethylpolysiloxane conforming to the above formula where n averagesbetween 3-6. Dow Corning 245 Fluid (Dow Corning) is a cyclic volatilesilicone which is commercially available. CTFA Cosmetic IngredientDictionary, Third Edition, (Estrin et al., Editors; The Cosmetic,Toiletry and Fragrance Association, Inc.; 1982) lists cyclic siliconeson page 60, under the entry "Cyclomethicone".

The liquid emollient ingredient of an invention cosmetic stick productis selected from one or more water-insoluble organic compounds which areliquid at 25° C. and which contribute a combination of properties thatare advantageous in an invention antiperspirant-deodorant cosmetic stickproduct.

The term "water-insoluble" as employed herein refers to an emollientingredient which has a water-solubility of less than about one weightpercent at 25° C.

A present invention emollient ingredient exhibits a low degree ofirritation and toxicity in topical applications, and provides asoftening or soothing effect on surface skin tissue.

Preferred water-insoluble liquid emollients include fatty acids such asoleic and ricinoleic; fatty alcohols such as oleyl, lauryl andhexadecyl; esters such as diisopropyl adipate, benzoic acid esters of C₉-C₁₅ alcohols, and isononyl isononanoate; alkanes such as mineral oil;silicones such as dimethylpolysiloxane and cyclic dimethylpolysiloxane;and ethers such as polyoxypropylene butyl ether and polyoxypropylenecetyl ether. Preferred water-insoluble liquid emollients includediisopropyl adipate, 2-ethylhexyl palmitate, dimethylpolysiloxane (50cst.), and polyoxypropylene (14) butyl ether.

The low melting point wax ingredient of a present invention cosmeticstick product comprises one or more organic compounds which have amelting point in the range between about 95°-180° F.

Suitable types of wax-like compounds include fatty acids, fattyalcohols, fatty acid esters, fatty acid amides, and the like, which havean aliphatic chain length between about 8-30 carbon atoms. Illustrativeof wax-like compounds are cetyl alcohol, palmitic acid, myristylalcohol, stearyl alcohol, paraffin, and the like, and mixtures thereof.

The low melting point wax ingredient can include up to about 30 weightpercent, based on the weight of wax ingredient, of a wax which has amelting point between about 180°-220° F. Illustrative of these highermelting waxes are beeswax, spermaceti, carnauba, bayberry, candelilla,montan, ozokerite, ceresin, paraffin, castor wax, Fischer-Tropsch waxes,and the like.

The antiperspirant ingredient of a present invention cosmetic stickproduct typically is a particulate astringent compound which has anaverage particle size between about 5-200 microns. Superior cosmeticstick properties are obtained if part or all of the antiperspirantingredient is in the form of particles which have a diameter less thanabout one micron.

Suitable astringent compounds include aluminum chloride, aluminumchlorohydrate, aluminum sulfocarbolate, aluminum sulfate,aluminum-zirconium chlorohydrate, zinc sulfate, zinc sulfocarbolate, andzirconium chlorohydrate. Preferred types of astringent compounds arealuminum chlorohydrates and aluminum-zirconium chlorohydrates, such asaluminum zirconium tetrachlorohydrex glycine which is commerciallyavailable as Rezal 36 GP Superultrafine (Reheis), and Reach AZP 908(Reheis). The organometallic astringent compounds tend to have lowerdensities which are advantageous for purposes of density matching of theorganic matrix phase and dispersed particle phase in an inventioncosmetic stick product.

The water-soluble inorganic salt deodorant ingredient of an inventioncosmetic stick product preferably is selected from alkali metal andammonium bicarbonates, such as sodium bicarbonate, potassiumbicarbonate, ammonium bicarbonate and mixtures thereof. The bicarbonatedeodorant ingredient can contain up to about 30 weight percent, based onthe weight of deodorant ingredient, of an alkali metal or ammoniumcarbonate compound.

The average particle size of the water-soluble inorganic salt deodorantingredient can be in the range between about 5-200 microns. Improvedcosmetic stick properties are obtained if part or all of the inorganicsalt ingredient has a particle size diameter less than about one micron.Colloidal size particles facilitate incorporation into the cosmeticstick matrix, and the resultant stick composition has a smoothernon-gritty feel when applied to the skin.

The term "water-soluble" as employed herein refers to an inorganic saltwhich has a solubility of at least about one gram per one hundred gramsof water at 25° C.

The optional surfactant ingredient of an invention cosmetic stickproduct can be selected from nonionic, cationic and anionic polymers.

Suitable surfactant polymers include cetyltrimethylammonium bromide;sodium lauryl sulfate; sodium dodecylbenzenesulfonate; ammoniumlignosulfonate; condensation products of ethylene oxide with fattyalcohols, amines or alkylphenols; partial esters of fatty acids andhexitol anhydrides; polyalkylene glycol esters; and the like.Illustrative of a preferred type of surfactant polymer is polyethyleneglycol (PEG) stearate, which is commercially available as PEG 600distearate.

Other optional ingredients also may be included in an invention cosmeticstick formulation, such as bacteriostats, fungistats, fillers,stabilizing agents, antioxidants, pigments, coloring agents, perfumes,hardeners, chelating agents, and the like.

A bacteriostat such as 2,4,4'-trichloro-2'-hydroxydiphenyl ether(Triclosan) typically is added in a quantity between about 0.08-3 weightpercent, based on the weight of the cosmetic stick product.

An optional ingredient such as colloidal silica suspending agent isadded in a quantity between about 1-3 weight percent, based on theweight of the cosmetic stick product.

An important aspect of the present invention is the provision of anantiperspirant-deodorant cosmetic stick product which is composed of asolid organic matrix containing a homogeneous dispersion of particulateantiperspirant and deodorant ingredients.

The solid organic matrix and dispersed particle phases have densitieswhich are sufficiently matched to prevent settling of the dispersedparticles during manufacture, and to provide a cosmetic stick productwith dimensional stability.

Antiperspirant and inorganic salt deodorant compounds nominally have adensity above about two grams per cubic centimeter. If high densityparticulate ingredients are suspended in an organic matrix having adensity of about one gram per cubic centimeter, the particles have atendency to settle out of the organic matrix, and the resultant cosmeticstick product is inhomogeneous and dimensionally unstable.

In the present invention, separation of organic matrix and suspendedparticle phases is prevented by providing particulate antiperspirant anddeodorant ingredients having densities which more closely match thedensity of the organic matrix of a cosmetic stick product.

One means of density matching is by the utilization of organic polymerpre-coated particles of antiperspirant and inorganic salt deodorantingredients in the manufacture of the antiperspirant-deodorant cosmeticstick product. Pre-coating of ingredient particles has the beneficialeffect of improving the suspension properties of the particles in thefluid formulation admixture during processing. Less particle settlingoccurs in the organic matrix because the density of the coated particlesand the organic matrix density are more closely matched than is the casewith uncoated particles. There is a tendency for uncoated particles tosettle out during the manufacturing process when the organic matrix isin a fluid state, and also in the cosmetic stick product when theorganic matrix is in a solid form.

The organic polymer coating on the dispersed antiperspirant andinorganic salt deodorant particles also has the benefit of minimizingany reaction between acidic antiperspirant and basic deodorantcompounds, and preventing loss of antiperspirant-deodorant activities.

The application of the coating to the particles is accomplished byconventional means such as pan coating, fluidized coating, centrifugalfluidized coating, and the like. The coating polymer usually isdissolved in a suitable solvent such as water, methanol, ethanol,acetone, tetrahydrofuran, ethyl acetate, dimethylformamide, and thelike, as appropriate for a selected polymer species. A coating polymeralso can be applied in the form of an emulsion or suspension. After thecoating medium is applied to the particles, the solvent medium isremoved by evaporation, thereby forming a continuous film coating whichencapsulates the individual particles.

The coating thickness on the particle surfaces typically will vary inthe range between about 0.1-20 microns. The coating can consist of asingle layer or multiple layers. The polymer coating can constitutebetween about 5-30 weight percent of the total dry weight of the coatedparticles. The average size of the inner core particle typically is inthe range between about 5-80 microns.

The polymer employed for coating the ingredient particles is selectedfrom hydrophilic water-soluble and water-dispersible organic polymers. Amixture of polymers can be employed, and a content of between about0.5-40 weight percent of a hydrophobic water-insoluble polymer, based onthe coating weight, can be included.

The term "hydrophilic" as employed herein refers to an organic polymerwhich has a water-solubility of at least about 0.5 gram per 100 grams ofwater at 25° C.

Suitable hydrophilic polymers for coating particles include gum arabic,gum karaya, gum tragacanth, guar gum, locust bean gum, xanthan gum,carrageenan, alginate salt, casein, dextran, pectin, agar, sorbitol,2-hydroxyethyl starch, 2-aminoethyl starch, maltodextrin, polydextrose,2-hydroxyethyl cellulose, methyl cellulose, carboxymethyl cellulosesalt, cellulose sulfate salt, polyvinylpyrrolidone, polyethylene glycol,polypropylene glycol, polyethylene oxide, polyvinyl alcohol/acetate,polyacrylamide, and the like. Polyvinyl acetate is illustrative of awater-insoluble polymer which can be included as an additional coatingcomponent to moderate the hydrophilicity of the coating.

The rate of particle matrix compound release from the particle coreunder moisture conditions can be controlled by the quantity and type ofhydrophilic polymer coating on the particle surfaces.

Low molecular weight hydrophilic polymers will release the particlematrix compound at a relatively fast rate in the presence of moisture.High molecular weight polymers which are less hydrophilic will releaseat a relatively slow rate. Additional rate control is obtained byemploying mixtures of polymer components of varied hydrophilicity.

Polyethylene glycol (M.W. of 4000) or polyvinyl alcohol will releaseparticle matrix compound at a relatively fast rate. Polyethylene oxide(M.W. of 4,000,000) or partially hydrolyzed polyvinyl acetate willrelease at a relatively slow rate. Polyvinylpyrrolidone will releaseparticle matrix compound at an immediate rate when in contact withunderarm type of moisture.

Another means of achieving density matching of organic matrix andsuspended particle phases is by the utilization of antiperspirant andinorganic salt particles which have a microporous structure.Microporosity in crystalline compounds can be achieved by variousmethods developed in chemical practice.

In one method, particles of the desired compound are prepared inadmixture with a second compound, such as by coprecipitation from asolvent medium. The second compound is selected so that it can beremoved from the particle mass by selective solvent extraction, or byheat treatment to convert the second compound into a volatile fraction.

Illustrative of this method is a coprecipitated mixture of sodiumbicarbonate and ammonium bicarbonate. Heat treatment of thecoprecipitate above 100° C. decomposes the ammonium bicarbonate tovolatile components, and the residual sodium bicarbonate can have alowered density in the range of 1-2 grams per cm³.

In another method of preparing microporous particles, an aqueoussolution of alkali metal bicarbonate can be diluted with an organicsolvent such as methanol, and the resultant precipitate is in the formof particles composed of agglomerated monoclinic needles of alkali metalbicarbonate. The needles have a crystal length between about 0.5-2microns, and the agglomerated particles have an average size betweenabout 4-12 microns in the largest dimension. The particles arecharacterized by a network of microporous voids between the agglomeratedneedles.

Another means of achieving density matching of organic matrix andsuspended particle phases is by the utilization of antiperspirant andinorganic salt particles which are coordinated with an organiccomplexing compound.

Alkali metal bicarbonate can form molecular complexes with organiccompounds such as β-cyclodextrin, mannitol, sorbitol, crown ether,trioxane, and the like. The density of the alkali metalbicarbonate:organic compound complex is less than the density of thefree alkali metal bicarbonate. A molecular complex can be obtained byevaporating an aqueous solution of the alkali metal bicarbonate andwater-soluble organic complexing compound.

In general, the ingredients of the cosmetic stick formulation can beblended in any order during manufacture. However, in the practice of theinvention process there is advantage in employing a phased order ofingredient addition and blending under controlled temperatureconditions. Additional advantage is obtained in the invention process ifthere is a short time lapse between an alkali metal bicarbonatedeodorant ingredient addition step and the cosmetic stick containerfilling and solidifying step. Alkali metal bicarbonate can convert toalkali metal carbonate, carbon dioxide and water at elevatedtemperatures.

Adding a bicarbonate deodorant as the last ingredient of the blendedformulation, and processing the formulation to the solid cosmetic stickformation stage within a short time period, are factors which minimizethe degradation of the bicarbonate ingredient, and the undesirableformation of water and carbon dioxide vapor byproducts. The addition andmixing of a bicarbonate deodorant ingredient into the formulation, andthe dispensing of the formulation into cosmetic stick containers, can beaccomplished as an essentially instantaneous procedure by utilizing anintegrated mixing valve nozzle device, such as the type described inU.S. Pat. Nos. 2,816,518; 3,454,198; 3,949,904; 4,318,429; 4,549,813;5,046,538; 5,094,276; and the like.

The practice of the invention process for the production of a cosmeticstick product can be conducted in conventional equipment, and is readilyadaptable to a commercial-scale manufacturing operation.

A present invention cosmetic stick product preferably has a hardnesspenetration value between about 4-12 millimeters, as determined byAmerican Society For Testing Materials (ASTM) Method D5.

A present invention antiperspirant-deodorant cosmetic stick product hasexceptional properties for treating or preventing perspiration andmalodor associated with human underarm perspiration. A present inventioncosmetic stick product can be applied effectively with safety andcomfort for reduction of underarm perspiration and offensive odors.

A present invention deodorant cosmetic stick product provides particularadvantage for users who wish to avoid the risk of skin irritation causedby the presence of an antiperspirant ingredient.

Because of the density matching of organic matrix and dispersed particlephases, an invention cosmetic stick product has improved dimensionalstability, and better esthetic appearance and "feel" when applied tohuman skin. The density matching of ingredients also has application inroll-on cosmetic products.

The following Examples are further illustrative of the presentinvention. The components and specific ingredients are presented asbeing typical and various modifications can be derived in view of theforegoing disclosure within the scope of the invention.

EXAMPLE I

This Example illustrates a procedure for coating a particulatebicarbonate deodorant compound with a water-soluble organic polymer inaccordance with the present invention.

Guar gum (15 g, Supercol, Aqualon Co.) is dissolved in 150 ml of 50%aqueous ethanol solvent. Sodium bicarbonate (100 g, 50-80 microns,Church & Dwight) is suspended in the solution medium with stirring.

The solvent medium is removed by evaporation under vacuum. A dryfree-flowing powder is obtained. The particles are coated with a guarfilm having an average thickness of 2-5 microns.

EXAMPLE II

This Example illustrates a fluidized bed procedure for coating anantiperspirant compound with a water-soluble polymer in accordance withthe present invention.

A fluidized bed vessel is utilized which is equipped with a Wursterair-suspension coater system (WARF) as described in U.S. Pat. Nos.4,568,559 and 4,877,621.

A coating solution is prepared by dissolving polyethylene glycol (45 g,Poly-G 2000, Olin Corp.), and propylene glycol butyl ether (10 g, PPG14, Americol) in ethanol (600 g).

Particulate aluminum zirconium tetrachlorohydrex glycine (600 g, 60-100microns, Reheis) is charged into the coating chamber.

Compressed air is introduced into the coating chamber, and the polymericcoating solution is sprayed on the air-suspended antiperspirant corematrix particles, until the coating weight is about 20% of the total dryweight of the coated particles.

The procedure is repeated, except that Hydroxypropylmethylcellulose(Methocel 60 HG, Dow Chemical Co.) is employed as the water-solublepolymer.

EXAMPLE III

This Example illustrates a pilot-plant procedure for the preparation ofan antiperspirant-deodorant cosmetic stick product in accordance withthe present invention.

A stainless steel tank is provided which is equipped with turbineagitation.

Silicone oil DC 245 (600 lbs, Dow Corning) is charged to the mixingtank. Agitation (55-65 RPM) is initiated, and heating the liquid mediumto 176° F. is commenced.

During the heating period, the following order of ingredients are addedto the stirred liquid medium:

    ______________________________________                                                           lbs.                                                       ______________________________________                                        diisopropyl adipate  60                                                       PPG 14 butyl ether (Americol)                                                                      40                                                       stearyl alcohol      340                                                      castor wax (MP-70)   60                                                       eicosanol            10                                                       PEG 600 distearate (Mazer)                                                                         40                                                       ______________________________________                                    

The mixture is stirred at 176° F. for about 30 minutes until theingredients are melted and the liquid medium is homogeneous. Thestirring speed is reduced to about 35 RPM, then Cab-o-sil M-5 (15 lbs,Cabot) and aluminum zirconium tetrachlorohydrex glycine (480 lbs,Reheis) are added. The temperature is maintained at 176° F. for about 40minutes until the fluid medium is uniform, and then the temperature islowered to 124° F.

Polymer-coated sodium bicarbonate 3 DF (140 lbs, Church & Dwight) and afragrance (6 lbs, 1FF 567-AT) respectively are added with stirring toSilicone oil DC 245 (245 lbs, Dow Corning) in a second mixing tank at atemperature of 124° F. to form a homogeneous suspension medium. Thesodium bicarbonate particles are pre-coated with guar gum as describedin Example I.

The contents of the two mixing tanks which contain heated fluid mediumare transferred to separate fill tanks through a Greer mill, and thefill tanks are connected to a mixing and dispensing nozzle device, ofthe type described in U.S. Pat. No. 5,094,276. The nozzle device isadapted for homogeneously blending the two separate streams of fluidmedia, and dispensing a predetermined quantity of the blended fluid.

Plastek 2 oz. bottom-fill stick containers are filled with the blendedfluid. The container contents are cooled to a room temperature solidstick over a period of about 45 minutes. The average hardness value ofthe solid sticks is 7 (ASTM Method D5).

Similar results are obtained when microporous sodium bicarbonate isemployed in place of the polymer-coated sodium bicarbonate ingredient.

A deodorant cosmetic stick product is prepared by eliminating theantiperspirant ingredient, and increasing the quantity of sodiumbicarbonate ingredient from 140 lbs to 180 lbs in the above describedmanufacturing process.

What is claimed is:
 1. A deodorant cosmetic stick product consisting ofa solid organic matrix comprising the following parts by weight ofingredients:

    ______________________________________                                        volatile silicone oil                                                                           10-55                                                       liquid emollient   1-35                                                       low melting point wax                                                                           12-30                                                       ______________________________________                                    

and the solid organic matrix has homogeneously dispersed therein betweenabout 1-40 parts by weight water-soluble inorganic salt deodorantingredient; wherein the dispersed particles have a density which is lessthan about one gram per cubic centimeter higher than the density of thesolid organic matrix, and an average particle size between about 5-200microns, and wherein the surfaces of the deodorant particles are coatedwith a hydrophilic polymer coating having a thickness in the rangebetween about 0.1-20 microns.
 2. A cosmetic stick product in accordancewith claim 1 wherein the deodorant ingredient is sodium, potassium orammonium bicarbonate or a mixture thereof.
 3. A cosmetic stick productin accordance with claim 1 wherein the polymer coating on the inorganicsalt deodorant particles has a polysaccharidic, oxyalkylene or polyvinylstructure.